Tools for the riveting for blind rivets in which the force necessary for deforming the blind rivet which consists of a hollow rivet and a pull mandrel which can be torn off is applied manually are known. They comprise generally a housing which terminates, for instance, in a fixed arm of a pair of tongs and of another tongs arm. The movable arm, which is rotatably supported in the housing bears or acts on the chuck mechanism. By operating the arms of the tongs, and particularly by closing the movable arm, the riveting is effected. The transmission of power upon an actuation is effected in this case generally by a lever arm between the mounting point of the movable arm and tong-arm handle on the one hand and the mounting point of the articulated chuck mechanism on the other hand. Due to the simple lever-arm arrangement these tools cannot be used for all sizes of rivets when working with blind rivets. To be sure, manual riveting tongs are known the arms of which are made particularly long in order to increase the force transmission ratio but they are subject to practical limits so that only blind rivets up to a certain maximum diameter can be riveted by hand with such tools.
For the riveting of blind rivets of larger diameter there are known manual riveting tools which are provided between the actuating lever or movable tongs arm and the chuck mechanism with a special device for the transmission of force. Such tools are known both in the embodiment with one tongs arm fixed on the housing and one movable tongs arm and in the embodiment with two movable tongs arms.
West German Provisional Pat. No. 1,216,656 describes such a manual riveting tool developed as so-called lever riveter, it consisting of a housing with one tongs arm rigidly connected to it and a tongs arm which is rotatably mounted in the housing. The chuck mechanism for gripping the rivet mandrel is borne by a rack which is displaceably arranged in the housing. Between the rotatable tong arm and said rack there is rotatably supported a segment-shaped gear wheel element for the transmission of force. The toothing on one end of the gear wheel element is in engagement with the rack while a pinion developed on the movable tong arm engages into the toothing at the other end of the gear wheel element. With this tool it is possible to rivet blind rivets with high tensile forces such as for instance 6 mm diameter blind rivets of Alu alloy or 5 mm diameter blind rivets of alloy steel with only slight manual expenditure of force. This manual riveting tool therefore has relatively long tong arms with a large opening angle. Due to the pre-established length of the tong arms, their arrangement and the space for movement necessary for actuation the known tool cannot easily be used in confined spaces for instance in a shaft, a drawer, on structural shapes, etc. since the riveting place either cannot be reached at all or the required space for movement is not available. Known riveting tools operated by external power without tong arms cannot always be used in such cases due to a lack of source of energy, such as for instance compressed air or electricity.